Greene, Tweed & Co. Common Sealing Materials


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Common Sealing Materials -  - Greene, Tweed & Co.
Kulpsville, PA, USA
Common Sealing Materials
NBR/HNBR NBR, or nitrile rubber (also commonly referred to as buna-N rubber or perbunan), is a synthetic rubber copolymer of acrylonitrile (ACN) and butadiene. Higher ACN content yields better resistance to hydrocarbon oils, while lower ACN content provides better flexibility in low-temperature applications. NBR seals with a medium ACN content (approximately 30-45%) are the most commonly used because of their balanced attributes and applicability to most environments. HNBR, or hydrogenated nitrile butadiene rubber, has a higher temperature rating than standard NBR, and also exhibits high tensile strength and great resistance to oil and chemicals. FEPM FEPM is the ASTM designation for a range of alternating copolymers of tetrafluoroethylene (TFE) and propylene. FEPM offers great heat and excellent chemical resistance to a wide range of aggressive media. EPM/EPDM Ethylene propylene (EPM or EP) rubber is a form of non-polar synthetic rubber that can only be cured with peroxide or radiation. EPDM consists of an additional monomer, diene, and can be cured using peroxide- or sulfur-based chemistries. EPM and EPDM seals only differ slightly in performance. Both present outstanding resistance to hot water/steam and polar solvents, along with excellent ozone resistance. AU Polyurethane (AU/EU/PU) rubber is most commonly formed by reacting a polyol with di- or poly-isocyanate. Polyurethane seals have high-wear, high-abrasion resistance, as well as great permeation resistance. CR Chloroprene, or CR, rubber is a synthetic rubber based on the organic compound, 2-chlorobuta-1, 3-diene. Chloroprene seals provide high resistance to heat, ozone, and weathering. FVMQ Fluorosilicone (FVMQ) is the common shorthand for fluorovinylmethyl silicone. Fluorosilicone elastomers perform well in a wide range of temperatures, from as low as -73°C (-100°F), and as high as 177°C (350°F). Because of limited tear strength and abrasion resistance, however, they are generally only used in static applications.
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  Greene, Tweed & Co.
Product Category Resins and Compounds
Product Name Common Sealing Materials
Industry Aerospace; Electrical Power or High Voltage; Semiconductors or IC Packaging
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